The effect of magnetic field on peristaltic flow through the gap between uniform tubes is studied under the assumption of long wavelength at low Reynolds number. The inner tube is rigid and the outer tube has a sinusoidal wave travelling down its wall. The flow is investigated in a wave frame of reference moving with the velocity of the wave. The analytical solution for velocities and pressure ...

We present measurements performed in a spherical shell filled with liquid sodium, where a 74-mm-radius inner sphere is rotated while a 210-mm-radius outer sphere is at rest. The inner sphere holds a dipolar magnetic field and acts as a magnetic propeller when rotated. In this experimental setup called "Derviche Tourneur Sodium" (DTS), direct measurements of the velocity are performed by ultraso...

Synopsis This chapter reviews theoretical approaches to calculating the energy and entropy budgets of the Earth’s core. The energy budget allows the growth of the inner core with time to be calculated; the entropy budget determines whether or not a geodynamo can function. The present-day geodynamo is driven primarily by compositional convection, with latent heat, secular cooling and (possibly) ...

In this report, the radiation of sound from an annular duct exit with buried inner nozzle system, with jet and bypass flow, is studied. This problem represents a simplified model of the radiation of fan and turbine noise from engine exhausts. The model consist of two semi-infinite ducts. The smaller duct (inner nozzle), whose exit plane coincides with the larger one or extends beyond it, is sit...

The flow in the gap between an inner rotating cylinder concentric with an outer stationary cylinder with an imposed pressure-driven axial flow was studied experimentally using particle image velocimetry ~PIV! in a meridional plane of the annulus. The radius ratio was h50.83 and the aspect ratio was G547. Velocity vector fields for nonwavy toroidal and helical vortices show the axial flow windin...